Three micro detectors were developed and studied using micro-liquidchromatography (micro-LC). An evaporative light scattering detector (ELSD) nebulizer was developed for use with flow rates ranging from 0.5 to 10 µL/min. The parameters that affect analyte response were investigated and the most influential were capillary tip position and nebulization gas flow rate. One unique advantage of thismicro detector is that it can be operated at ambient conditions which allows for the analysis of semi-volatile compounds.

A radio activity monitor (RAM) flow cell was developed for use at 3 µL/min and was designed for coupling to mass spectrometry (MS). The parameters that affect analyte response and band broadening were studied. Reducing the solid scintillant particle size to 9 µm and efficiently packing the solid cells allowed for direct coupling to MS without compromising the chromatographic separation.

A nano-electrospray ionization (BSI) source for MS was developed and coupled to nano-LC and capillary electrophoresis (CE). This source incorporated a 50 µm i.d. stainless steel tip that was coupled to the separation capillary. At flow rates of 100 nL/min a stable electrospray was achieved.

A multi-use separations system was developed for isocratic and gradient elution micro-LC, capillary electrochromatography (CEC), and pressure CEC (PEC). The details of the system and studies on peak area and retention time repeatability are reported. Comparisons are made between nano-LC and CEC. On average, column efficiency is 57% greater for CEC compared to nano-LC using the same nanocolumn.

An automated liquid nano-separation system has been developed for nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) using both isocratic and gradient elution, One fused-silica nanocolumn, typically 75 mu m i x 39 cm (25 cm ef

With the knowledge of the composition and structure of a chemical system, be it a molecule, a two-dimensional surface or a three-dimensional crystal, it is now possible to predict the specific properties of the compound under consideration via computational studies. Molecular and periodic Hartree-Fock and DFT calculations have been used as a tool to study polar molecules and how their properties respond to the molecular environment in a crystal or on an ionic surface. The investigation covers a range of molecules (HF, HC1, HCN, H2O, OH-, OH., N2, CO and LiF) with different net charges, dipole moments and polarisibility, and a range of crystals and crystalline surfaces: hydrogen-bonded, ionic and ferroelectric.

The step-wise build up of the molecular properties (geometries, energies, dipole moments, vibrational frequencies etc.) has been investigated. It was found that sorne molecular properties converge quickly towards the crystal value, others more slowly. Molecules adsorbed on a solid surface were studied as a function of adsorptionenergy, substrate and surface coverage. For the ionic surfaces studied here it was found that the properties of the chemi- and physisorbed molecules are as sensitive to the surface coverage as to the adsorption of the ad-molecule to the surface. The vibrational frequency shift of the ad-molecule has been given special attention.

Finally the spontaneous polarisation in two ferroelectric crystals was calculated within the Berry-phase approach.

A highly diastereoselective reaction of 2-azanorbornyl enolates with electrophiles has been studied. Deprotonation of 4 with LDA at low temperature affords the corresponding exocyclic lithium enolate 5, which reacts with different electrophiles such as al

The mechanism of the Ru(arene)(amino alcohol)-catalyzed transfer hydrogenation of ketones using isopropyl alcohol as the hydrogen source has been studied by means of hybrid density functional methods (B3PW91). Three mechanistic alternatives were evaluated, and it was shown that the reaction takes place via a six-membered transition state, where a metal-bound hydride and a proton of a coordinated amine are transferred simultaneously to the ketone. Further calculations provided a general rationale for the rate of the reaction by comparison of steric effects in the ground and transition states of the ruthenium hydride complex. It was found that the TS has a strong preference for planarity, and this in turn is dependent on the conformational behavior of the O,N-linkage of the amino alcohol ligand. Finally, a general model, rationalizing the enantioselectivity of the reaction, was developed. Experimental studies of both rate and enantioselectivity were used in order to support the computational results.

An extremely simple design has been developed for producing durable sheathless electrospray emitters that give highly stable electrospray for unlimited lifetimes. The emitters can be fashioned from any style fused-silica capillary and are ideally suited

The transition-metal oxide spine1 LiMn2O4 is a promising cathode material for high-capacity lithium-ion batteries. Structure-property relationships pertaining to the electrochemical cycling behaviour of LiMn2O4 have been studied. The techniques exploited have been in situ X-ray and neutron diffraction, in combination with quantum-mechanical band-structure calculations. The results obtained lay the ground for an improved basis for designing new insertion materials.

Substitution of Mn by Ni in LiMn2O4 and by Li in Li1+xMn2-xO4 give qualitatively different results: Ni is found to replace Mn directly, while Li takes up entirely new sites not observed earlier. Band-structure calculations have been used to better understand the crystallographically observed x-dependence of the Li1+xMn2-xO4 structure, and the underlying mechanisms of lithium-ion extraction/insertion.

Quantitative observation of charge passed through the cell has also been related to the amount of lithium extracted to indicate possible sources of irreversible capacity loss, and how synthesis technique can influence cell performance.

The LiMn2O4 structure has also been studied by neutron diffraction after treatment in strong-acid solutions, where Li ® H ion-exchange has been observed to take place. This process has strong implications for the dissolution of Mn2+ ions from the cathode into the electrolyte, especially at elevated temperatures, and the related corrosion process occurring at the cathode surface.

The current response of a 10-mu m walt-tube microelectrode in a now injection system under the conditions of low ionic strength has been examined experimentally for several redox systems such as ferrocene in methanol, undiluted methanol, and water in ace

Amperometric determinations of the water content in acetone, butter and margarine were performed using a wall-tube platinum microelectrode in combination with a flow injection system. For the butter and margarine samples, acetone containing small amounts

The influence of diffusional, migrational and convective mass transport at microelectrodes employed for voltammetric and amperometric detection in flowing solutions has been investigated. Special attention was paid to the influence of convection on the IR drop in organic solvents and on the transport of reaction products between individual electrode bands of microarray electrodes. A flow injection system was also designed to study the stability of mercury films coated on microelectrodes for the purpose of stripping analysis.

Increased influence of convection, obtained by altering the flow rate or by changing the position of the microelectrode in a wall-tube flow cell, at low support ratios in organic solvents was found to result in decreased currents as a consequence of the inability to maintain a sufficient amount of ions at the vicinity of the microelectrode surface. Successful determinations of the water content in butter and margarine could be performed in an acetone based flow injection system, provided that the detection potential was chosen to accommodate the different support ratios in the injected solutions.

The degree of redox cycling at interdigitated microarray electrodes was found to increase if the flow rate was reduced from 20 to 2 µl/min. Even at these low flow rates, the degree of redox cycling in stationary solutions was, however, always larger compared to the values obtained under the influence of convection. A microarray electrode was also employed to improve the selectivity in the detection of poorly separated species in capillary electrophoresis.

By employing a flow injection system, it was found that the stability of mercury films plated on platinum and carbon fibre microelectrodes could be improved as potential control could be maintained during solution exchange and between individual experiments. Stripping voltammetric determinations of nickel at nM concentrations and of copper in a low ionic strength solution was demonstrated in the flow injection system.

The electrochemical properties of a number of azosalicylic acid derivatives have been compared at glassy carbon electrodes using cyclic and hydrodynamic voltammetry. The reduction of all studied compounds, except one, was found to be irreversible giving

A strong anion-exchanger was used as a trapping column to perform on-line coupling of ion-pair chromatography with electrospray ionisation mass spectrometry. Ion-pairing reagents were used to retain polar analytes of low molecular mass away from the solv

The stability of group 8-10 silicides has been studied by LMTO-ASA band structurecalculations. In the Rh-Si and Ir-Si systems the lowest calculated heat of formation isfound in compounds near the equiatomic composition. Model calculations forsuperstructures in bcc and fcc solid solutions show that in group 8 and 9 silicides thebcc based structures have a maximum in stability near 50% Si. In group 10 systemsthe energy minimum is shifted to lower Si contents and the minimum is less clearlydeveloped.

The heats of formation in monosilicides are predicted to have a minimum for metalatoms from group 9.

Calculated one electron densities of states are in good agreement with spectroscopicmeasurements and confirm the generally accepted picture of silicide stability. Themain stabilising factor is metal d - silicon p bonding. With increasing Si contents or group number of the metal atoms dp antibonding states become increasingly filled. A stabilising effect in the highest occupied states is metal-silicon pp interactions and insilicon rich compounds also silicon-silicon pp interactions.

When packed capillary columns are coupled to electrospray mass spectrometry, care must be taken to reduce the dead volumes of the detector connections. In this work, the coupling between the column and the detector was made with a 20-mu m i fused silica

Pneumatically assisted electrospray mass spectrometry was evaluated as a complementary detection technique to UV absorbance, for determination of specific radioactivity of tracer molecules to be used in positron emission tomography. Tracers labelled with

The enantiomers of metoprolol, a frequently used beta-blocker, have different physiological effects, which makes their chiral separation necessary. The separation of the main product from its by-products and their chiral separation were also aims of this

Some examples of recent development of the synthesis of compounds labelled with short-lived beta(+)-emitting radionuclides will be discussed with an emphasis on the importance of time in selecting a synthetic strategy. Furthermore the use of such labelle

Applications of magnetic materials are inherently related to their crystal, magnetic and electronic structures. In this thesis, experimental and theoretical methods have been focused on magnetic bulk materials from novel chemical synthesis, to X-ray diffraction for initial phase characterisation, and crystal and magnetic structure studies to explain their complex magnetic properties. A selection of materials was studied, ranging from 3d transition-metal phosphides to rare-earth transition-metal intermetallics. Several techniques (including X-ray and neutron diffraction, magnetisation measurements,Mössbauer spectroscopy and first principles, electronic structure calculations) were combined to obtain a unified picture.

In the (Fe1-xCox)3P compounds (x<0.37), a dependence of structure and ferromagnetic properties on Co concentration was demonstrated. The situation for the (Fe1-xMnx)3P system is more complex and has been studied at both ends of the composition range. At the Fe-rich end (x<0.25), the compounds exhibit ferromagnetic ordering, while at the Mn-rich end (x≥0.67), an antiferromagnetic coupling was discovered. The majority of the experimental results are supported by theoretical calculations.

Magnetic ordering in the TbNi5-xCux system was determined, starting with the incommensurate modulated helimagnetic structure for the binary compound TbNi5, and going over to the collinear ferromagnetic structure for the Cu-substituted pseudo-binary system.

The phase stability investigation of CePt2Sn2 was made using in situ X-ray powder diffraction with respect to tetragonal and monoclinic modifications. The crystal structures were determined by the Rietveld refinement method.

Microfabricated arrays consisting of four individually addressable band electrodes have been used for end-column electrochemical detection in capillary electrophoresis (CE), The commercially available array was positioned 75-300 mu m from the capillary o

End-column electrochemical detection based on either the use of a 25 mu m microdisk electrode or a 0.5 mm macrodisk electrode has been compared with respect to performance and influence on non-aqueous capillary electrophoretic separations. Despite the mu

The high electric and thermal conductivity of copper has made it to a prime candidate as interconnect material in future integrated circuits. In this thesis, Atomic Layer Epitaxy has been used to deposit thin copper films on a variety of substrates, using both CuCl and Cu(II)2,2,6,6-tetramethyl-3,5-heptanedionate, Cu(thd)2, as precursors and hydrogen as reducing agent. Besides the experimental work, this thesis also comprises a large theoretical investigation where calculations based on Density Functional Theory has been performed in order to elucidate the deposition mechanisms in the CuCl/H2 process.

Experiments showed that highly pure copper with low resistivity could be selectively deposited in the Cu(thd)2 process on Pt/Pd seeded substrates at temperatures below 300 °C. At higher temperatures, a selectivity was lost due to a thermal decomposition of the precursor, The selectivity was explained by the high catalytic activity of the seedlayer.

Copper deposition by means of the CuCl/H2 process was kinetically controlled with an activation energy of approximately 85 kJmol-1 in the reduction step. Calculations showed that the rate determining step was the surface reaction between hydrogen and CuCl.

Nuclide therapy for cancer is based on the selective delivery of nuclide bearing compounds to tumour cells. Radionuclides, such as 125I, may be used, as well as stable isotopes, such as 10B, which is activated on site by an external neutron source. The second methodology is used in Boron Neutron Capture Therapy, which utilises the cytotoxic effect from the neutron capture reaction 10B(n,α)7Li. With this background in mind, nuclide bearing amino acids, nucleosides, and isoquinolines have been synthesised.

Carborane containing analogues of phenylalanine were asymmetrically synthesised using Oppolzer's camphor-derived chiral handle. The (R)- and (S)-[3-(1,7-dicarba-closo-dodecaborane(12)-1-yl)-2-aminopropanoic acid] (meta-carboranylalanine), were obtained in >99 % enantiomeric purity. The (S)-Boc-ortho-carboranylalanine was obtained in two steps from (2S,2'S)-N-(3'(1",2"-dicarba-closo-dodecaborane(12)-1"-yl)-2'-aminopropanoyl)bornane-10,2-sultam.

The carborane containing isoquinoline derivative N-Methyl-N-(1-methylpropyl)-l-[2'-(l"-7"-dicarba-closo-dodecaborane(12)-l"-yl)ethyl]isoquinoline-3-carboxamide was synthesised as a potential PBR-ligand.

A study on the transformation of TlCu5Se3 to the metastable orthorhombic form of TlCu4Se3 upon copper leaching has been conducted using neutron powder diffraction at 10 K and 293 K. The occupancy of the various copper sites in the TlCu5Se3 structure was investigated with Rietveld profile refinement techniques in combination with elemental analysis. The results indicate that mainly one of the three copper sites in the parent compound is affected during the extraction process.

In this thesis the development of an asymmetric version and synthetic applications of the Pd(II)-catalyzed 1,4-oxidation of conjugated dienes are described. The thesis is divided into four parts:

(i) The first part concerns the design and synthesis of chiral p-benzoquinones as ligands in the Pd(II)-catalyzed 1,4-diacetoxylation. A p-benzoquinone substituted with a tert-butyl group and a chiral sulfoxide was found to be the best ligand. Optimization of the reaction conditions yielded an enantiomeric excess of 45%.

(ii) The asymmetric version of the Pd(II)-catalyzed 1,4-dialkoxylation was also examined. In this case a C2-symmetric p-benzoquinone, with aminoalcohols as chiral units, was the best ligand employed in the reaction, and gave enantioselectivities up to 54% ee. The mechanism of the reaction is discussed.

(iii) The synthesis of various heterocyclic compounds utilizing the intramolecular version of the 1,4-oxidation is described. In this study hydroxyl or nitrogen groups were used as the internal nucleophile and various alcohols were employed as the second nucleophile. Both spirocycles and fused heterocycles were obtained. When the hydroxyl group was used as the internal nucleophile the products were generated in good to excellent yield with high regio- and stereoselectivities. With nitrogen as the internal nucleophile the regioselectivity was found to be dependent on the nature of the second nucleophile.

(iv) In the last part of the thesis the synthesis of epibatidine and its phenyl analogues are described. Here, one of the key-steps is the Pd(II)-catalyzed 1,4-chloroacetoxylation of aryl substituted 1,3-cyclohexadienes giving only one regio- and stereoisomer in moderate to good yields. Another key-step is a stereoselective hydrogenation, which afforded the required 1,2-cis or 1,2-trans relationship between the nitrogen and the aryl substituent.

In this thesis the use of palladium and ruthenium, with the latter in combination with enzymes, as selective catalysts in the transformation of organic substrates is discussed. The thesis is divided into two parts.

The first part concerns the use of palladium(II) as a catalyst for the 1,4-oxidation of conjugated dienes using allylsilanes and carboxylic acids as internal nucleophiles. The reaction employing allylsilanes has been studied with two different reoxidation systems, p- benzoquinone and copper(II) chloride. By using the former oxidant highly stereoselective reactions took place, whereas the use of copper(II) chloride gave mixtures of isomeric products. It was demonstrated,by isolation and characterization of (p- allyl)palladium intermediates, that the allylsilane reacted as a nucleophile on the diene. The reactions using carboxylic acids as nucleophiles were conducted with the internal nucleophile connected to the side chain in the 2-position of the diene, giving six-membered lactones in good yields. High stereoselectivities across the diene were obtained, but in some cases the regioselectivity was lower and the 1,2-addition product wasformed.

In the second part, studies of the combination of a ruthenium-catalyzed racemization with an enantioselective enzymatic acylation, in order to achieve a dynamic kinetic resolution ofsecondary alcohols, are described. It was found that the combination of a lipase from Candida antarctica, a stable ruthenium(II)-catalyst and a specifically designed acyl donor gave enantiomerically pure secondary acetates in good yields. Application of the reaction to symmetric diols gave enantiomerically pure diacetates in good yields and with high diastereoselectivities.

A versatile method for the preparation of indolizidine alkaloids from 1-benzyloxy-5-(p-toluenesulfonamido)-3-alken-2-ols as stereodefined key intermediates has been developed. The utility of this approach was demonstrated by the synthesis of (+)-monomorin

The choice of electrospray ionisation/time-of-flight mass spectrometry (ESI/TOF-MS) as mass analyser for combination with microseparation techniques, such as mu LC, CE and CEC, may be recommended due to the features that present-day TOF-MS instruments ha

A recently developed microelectrochemical detector for packed capillary column supercritical fluid chromatography (pcSFC) has been applied to determine nanogram amounts of tocopherols and vitamin A in vegetable oil samples. With this procedure, no remova